Elon Musk’s SpaceX stands to make history today as it gears up to launch its Falcon 9 rocket for the second time. Repeating this feat is exactly what makes tonight’s launch a historic moment — for the first time, SpaceX’s “reusable rocketry” will be on display.

The rocket taking off tonight is the same one that famously made an upright landing on a floating barge in 2016. Reusable rockets have been central to the company’s business plan since it was founded in 2002. As rockets are big and expensive, SpaceX aims to significantly reduce the costs of space travel by getting multiple uses out of the same hardware. The aim is to make rockets more like airplanes; they fly, land, refuel, and fly again.

Some companies have made limited progress with reusable rockets in the past. Jeff Bezos’s Blue Origin, for example, has re-flown rockets at not-quite-outer-space altitude for testing purposes. But this time, it’s different: SpaceX is going all the way to space to put a satellite called the SES-10 into orbit 22,000 miles above the Earth for a paying customer.

Tonight’s launch is scheduled to go off at 6:27 p.m. Eastern Time. There are a few ways to watch. You might make your way to the Kennedy Space Center in Cape Canaveral, Florida, to see it happen in person. But more likely, you’ll want to tune in to the live broadcast above, which will begin around 5:30 p.m.